Method for production of concrete reinforcement lattice mats

ABSTRACT

A method and apparatus for forming wire mats for reinforced concrete in which wire is drawn from a reel and successively directed to parallel, adjacent support tubes, the wire being successively cut after a predetermined length of the wire has been deposited into a respective tube. The cut lengths of wire constitute the longitudinal wires of the mat, and these lengths are advanced from the tubes as a unit and fed into a welding machine where transverse lengths of wire are welded to the longitudinal wires at points of intersection.

United States Patent 1191' Palmer 1 June 11, 1974 METHOD FOR PRODUCTION OF [56] References Cited CONCRETE REINFORCEMENT LATTICE UNITED STATES PATENTS MATS 2,712,837 7/1955 Griesamer 140/112 Inventor: oskar Palmer, Rembrandtst asse Samuels 12 X 25, 4 Dusseldorf, Germany P E I R h d B L rlmafy xammer- 1c ar azarus [22] Sept 1973 Attorney, Agent, or FirmWaters, Roditi, Schwartz & [211 App]. No.: 394,719 Nissen Related U.S. Application Data [57] ABSTRACT [62] Division of Ser. No. 252,477, May 11, 1972, Pat. No.

3,779,445 A method and apparatus for forming wire mats for reinforced concrete in which wire is drawn from a reel [30] Foreign Application Priority Data and successively directed to parallel, adjacent support M 2 197] G 212350 tubes, the wire being successively out after a predeteray many "f mined length of the wire has been deposited into a respective tube. The cut lengths of wire constitute the [52] Cl 29/471'3 29/429 longitudinal wires of the mat, and these lengths are ad- [51] I t Cl 823k 31/02 vanced from the tubes as a unit and fed into a welding [58] 471 3 475 machine where transverse lengths of wire are welded to the longitudinal wires at points of intersection.

6 Claims, 3 Drawing Figures 1 METHOD FOR PRODUCTION OF CONCRETE v REINFORCEMENT LATTICE MATS CROSS-RELATED APPLICATION This application 'is a division of application Ser. No. 252,477, filed May 11, 1972 now U.S. Pat. No. 3,779,445 and claims the priority of the application filed in Germany on May 12, 1971.

BACKGROUND 1. Field of the Invention The invention relates to a method for producing lattice mats for concrete reinforcement purposes consisting of longitudinal and transverse wire, in which a plurality of parallel wires, which are supplied from wire rings and which are pre-hardened and straightened before or after their being pulled from the rings, are assembled to the final length of the longitudinal wires in the lattice mat and then forwarded to a lattice welding machine in which the longitudinal wires are connected to the transverse wires so as to form a lattice mat. The invention also relates to apparatus for producing the lattice mats by the above method.

2. Prior Art In a conventional method for forming lattice mats, one wire rod ring is provided for each longitudinal wire. Prior to introducing the wire rod into the lattice welding machine, the wire is cold hardened in a wire stretching apparatus, and, subsequently thereto, is run through a straightening device. As a result of the simultaneous drawing of all longitudinal wires from the wire rod rings, there must be provided one wire stretching apparatus and one wire straightening device for each longitudinal wire. In case it is intended that the wires be additionally provided with ribs, an additional ribbing device must be provided for each longitudinal wire. As a result of the different tightness of winding in the wire rod rings, the method of simultaneous drawing of all longitudinal wires is prone to developing frequent breakdowns. Since the wire rod rings, as a rule, are not of exactly equal capacity, the production process must be stopped every time when one of the wire rod rings is consumed. The thus caused production losses are considerable, resulting fromthe large number of the wire rod rings neededfor this method. In order to minimize the time needed for exchanging the wire reels, a crane must be always available in order to insert the new wire rod.

In an another conventional method forproduction of lattice mats for concrete reinforcement purpose, the wire rod is first straightened and provided with ribs in a cold operation. The ribbed wire is then stored in rings until the time of its further processing to a lattice mat. It is necessary in the further processing of the wire into a lattice mat that the wire stored in rings be again straightened prior to its forwarding to the lattice weld ing machine.

SUMMARY OF THE INVENTION It is an object of the present invention to develop a method which makes possible continuous production of lattice mats for concrete reinforcement purposes by means of a relatively inexpensive apparatus.

This object is achieved according to the invention in a method of the above mentioned type in such a manner, that the assembling operation for the longitudinal parallel to and adjacent the longitudinal wire which has a rod which is alreadyin its final position. The rods which have already been drawn are retained in their final positions until the time when the entire family of longitudinal rods for a lattice mat is assembled. The method according to the invention does not require any transportation devices to transport the drawn longitudinal rods away in order to assemble them at another place in a family of longitudinal rods and to place them in a proper position therein so as to produce a lattice mat. The manufacturing process can be accomplished continuously, since the end of the wire rod ring can be connected to the beginning of the next wire rod ring during the drawing operation.

Advantageously, two families of longitudinal wires are assembled alternately one after the other, wherein one family of longiutdinal wires which has already been assembled is forwarded to the welding machine while the other famuly of longitudinal wires'is being assembled. In this embodiment of the invention the production of the lattice mats is achieved continuously, since there is no need for a waiting period after one family of longitudinal wires has been assembled to allow for the transportation of this family of longitudinal wires to further operational stages before the assembling operation of another family of longitudinal wires can be started.

The process according to the invention is particularly advantageous in manufacturing and technical respects, when the lattice mats are to be manufactured from shaped wire. In this case, according to a further embodiment of the invention, the wire rod is cold deformed after the drawing operation, for instance, provided with ribs by means of rolls. The drawingand the straightening operations in such case and using this method can be accomplished by means of a driven rib rolling device. The mutually welded beginnings and ends of the wire rod rings to be drawn subsequently to each other are equalized in the rib rolling device, so

that they disappear in the final product.

An apparatus which is particularly suitable for accomplishment of the method according to the invention comprises: a storage reel from which a single wire rod can be drawn by means of a drawing device provided with a straightening device; and a pivotable switching means which is located behind thedrawing device and which guides the wire rod, the switching means having a front end facing the entrance funnels of guides adapted to receive the wires. The switching maans introduces the front ends pf the longitudinal wires into successive guides. The guides are generally According to still another embodiment of the invention, in order to ensure absolutely continuous production of the lattice mats, two groups of parallel guides are provided and located above each other, and as a group their entrance funnels are alternately positioned adjacent the outletend of the switching means.

The particular advantages of the invention are seen in the face that the method according to the invention can be accomplished by use of a relatively inexpensive device, since only one drawing device, and possibly one cold deformation device, are needed for the assembling operation of the longitudinal wires of a lattice mat from a single wire rod. Conversely, the conventional devices for production of lattice mats require one drawing and one cold forming device for every longitudinal wire. The breakdowns, in the production, which result from the different tightness of winding of the wire rod rings in the process of simultaneously drawing a large number of parallel'extending longitudinal wires, are not encountered in the device according to the invention. The drawing of the wire rods for the longitudinal wires is accomplished continuously in the method of the invention, since the end of one ring is attached to the beginning of the next ring. A crane does not have to be immediately available for the exchange operation of the empty reels, since the exchange operation may be accomplished any time during the drawing operation of the wire from the other reel, i.e., in the course of continuous production.

BRIEF DESCRIPTION OF THE DRAWING The invention will be explained in greater detail with reference to an embodiment of the invention as illustrated in the accompanying drawing wherein,

FIG. 1 is a top plan view showing diagrammatically two adjacent devices for production of lattice mats for concrete reinforcement purposes according to the invention;

FIG. 2 is a side elevational view of the arrangement in FIG. 1', and

FIG. 3 is a diagrammatic illustration of the device according to FIG. 1 as seen in the direction of the arrow A-B.

DETAILED DESCRIPTION Two devices are shown in FIG. 1 for forming longitudinal wires of reinforcement mats, each of the devices including a rotatable storage reel 1 which carries two rings of wire rod. The end of the first wire rod ring is welded to the beginning of the second wire rod ring in a butt weld. The wire rod 2 is drawn off from the first wire rod ring by means of a drawing device 3, and fed to a switching means 4, whose rear end is pivotably supported on the drawing device 3 in a position to receive the wire discharged therefrom. The switching means 4 is laterally tiltable so that the wire rod emerging from the switching means 4 can be guided in succession to the entrances of adjacent parallel tubes 5 which serve as guides for the wire. A cutting apparatus 6 is provided between the outlet of the switching means 4 and the entrances of the tubes 5, said cutting apparatus being provided with a cutter bar. The tubes 5 are arranged in two groups which are located above each other as seen in FIG. 3. The individual groups of tubes 5 can be raised or lowered by means of a threading device 7, so that the tubes can be positioned so as to be in alignment with the wire rod emerging from the cutting apparatus 6. A transporting device 8 is mounted at the exit openings of the tubes 5, the transporting device being provided with two rollers, behind which there is provided a stop 9 which is selectively tiltable out of the moving path of the longitudinal wires. It can be seen in FIG. 2 that the exit openings of the tubes 5 are located at the same elevation at the inlet of the transporting device 8. A welding machine 10 is mounted behind the transporting device 8, in which the family of longitudinal wires introduced into the same is welded to transversely introduced transverse wires. The family of longitudinal wires are fed by transporting device 8 into machine 10 and a transverse wire is fed across the longitudinal wires and is welded thereto at the points of intersection, whereafter a further length of the family of longitudinal wires are advanced by device 8 into machine I0 and the operation repeated. When it is desired to manufacture lattice mats with shaped longitudinal wire from heated rolled rods, the drawing device 3 is constituted as a ribbing device with driven shaped rollers. The wire is formed with ribs thereon by cold deformation in the ribbing device.

The device according to the invention operates as follows:

The wire rod 2 is drawn off from the storage reel 1 by means of the drawing device 3 and is inserted in the tubes 5 under the control of the switching means 4. In the position of both tube groups as shown in FIG. 2, the wire rod-is inserted in the lower group of tubes. The filling of the various tubes 5 is accomplished in such a manner, that the wire rod is inserted in a first tube until it abuts against the stop 9. Then it is cut off by means of the cutting apparatus 6. The switching means 4 is then indexed by being tilted' laterally and the wire rod is inserted in the next tube adjacent the now filled tube in the same manner. The family of the longitudinal wires is assembled in this manner. At the left end of FIG. 1 there is diagrammatically shown five wire lengths placed in the tubes, the switching means 4 being positioned to place the sixth wire. After the en-. tire family has been assembled, the entire family of lon gitudinal wires is forwarded to the welding machine (after the stop 9 has been lifted) by means of the rollers of the transporting device 8. After the first group of tubes has been filled with wires, the other group of tubes, which is empty, is aligned with the switching means 4 by being raised or lowered and filled in a similar manner while the already assembled family of longitudinal wires in said first group of tubes is being fed to the welding machine, At the right end of FIG. 1, there is diagrammatically shown the discharge of the mat from the welding machine 10.

The arrangement according to the invention of two devices adjacent one another is advantageous with respect to the stacking of the completed mats insofar that. the mats can be so manufactured in respect to the longitudinal and transverse wires as to be mirror images of each other, so that they can be easily stacked bya simple superposition so as to require minimum space.

The indexing control of the switching means 4 can be manually achieved under visual control by an operator or it can be effected automatically in a manner wholly obvious to those skilled in the art of automatic control devices of this sort. Similarly, the feed of the family of wires 11 to the welding machine can be achieved by manually controlling initiation of the drive of the rollers in the transporting device 8 when all the tubes 5 are filled with wires, or this can be effected automatically.

transverse wires of the mat are successively welded to the longitudinal lengths of wires.

2. A method as claimed in claim 1 comprising successively guiding the wire drawn from the supply ring to the respective parallel locations in said mat.

3. A method as claimed in claim 2 wherein each length of wire is cut after it has been guidably advanced into its respective position in the mat.

4. A method as claimed in claim 3 wherein the wire is successively brought into contact with an abutment at each location of the mat to establish the length of wire to be cut at such location.

5. A method as claimed in claim 2 comprising forming two units of longitudinal wires for respective mats in alternation, and feeding one of the units to the welding machine while the other unit is being formed.

6. A method as claimed in claim 2 comprising cold deforming the wire as it is being drawn from the ring and being fed to the final location in the mat. 

1. A method for producing lattice mats for reinforced concrete structures, the lattice mats being composed of longitudinal and transverse wires, said method comprising drawing wire from a supply ring, cutting the wire in equal lengths in succession after each wire length has been positioned in its final location in the mat in parallel relation with the other wires in the mat, the lengths of wire being successively placed in adjacent longitudinal relation in the mat, and feeding the lengths of wires as a unit to a welding machine where transverse wires of the mat are successively welded to the longitudinal lengths of wires.
 2. A method as claimed in claim 1 comprising successively guiding the wire drawn from the supply ring to the respective parallel locations in said mat.
 3. A method as claimed in claim 2 wherein each length of wire is cut after it has been guidably advanced into its respective position in the mat.
 4. A method as claimed in claim 3 wherein the Wire is successively brought into contact with an abutment at each location of the mat to establish the length of wire to be cut at such location.
 5. A method as claimed in claim 2 comprising forming two units of longitudinal wires for respective mats in alternation, and feeding one of the units to the welding machine while the other unit is being formed.
 6. A method as claimed in claim 2 comprising cold deforming the wire as it is being drawn from the ring and being fed to the final location in the mat. 